CN101042395A - Method for measuring shearing bond strength between fibers - Google Patents

Abstract

This invention provides one method to test fiber shear combination intensity, which comprises the following steps: a, under certain humidity pressure or slurry intensity to test fiber shape parameter k; b, measuring paper zero distance stretching intensity Z and T and light diffusion parameter S; c, computing train combination intensity index; d, drawing train combination index of PBSI and light diffusion parameters relation pattern; e, computing shear combination intensity of b value by relation pattern. This invention combines light diffusion parameter test technique for one simple measurement of single fiber shear combination intensity.

Description

A kind of method of measuring shearing bond strength between fibers

Technical field

The present invention relates to the measuring method in the pulping and paper-making, particularly a kind of method of measuring shearing bond strength between fibers.

Background technology

In the pulping and paper-making field, measurement for shearing bond strength, measure relatively difficulty of tiny fiber of microcosmic and interfibrous shearing bond strength, macroscopical bond strength that now commonplace is measures page reflects the size of interfibrous shearing bond strength.Its measuring method mainly contains macroscopic measurement method (plurality of fibers measuring method) and microscopic measurement method (single fiber measuring method); In relatively outstanding having aspect the macroscopic measurement method: Z is to bond strength mensuration (Z～directional TensileTest), page layering mensuration (Delamination Test), Scott bond strength mensuration (ScottBond Test), the linear and ultrasonic Method for Measuring set up etc. of the intensity of utilizing planar ultrasonic wave elastic modulus (In～plane UltrasonicModulus) and page in addition in addition.Wherein, Z is the oldest a kind of method to the bond strength mensuration, and sensitivity is good but more time-consuming, for the big page of adhesion, needs to fix page with epoxy type adhesive; Need the cost regular hour like this, and must be carefully in order to avoid bonding agent infiltration page and influence the result.Page layering mensuration test speed comparatively speaking wants fast, but it is not suitable for quantitatively too low page.Scott bond strength mensuration is subjected to dynamic property (Dynamic Nature) influence of page quantification and proving installation easily, thereby is easy to get the result bigger than actual conditions.Above-mentioned three kinds of measuring methods mainly are to measure the merit (J/m that breaks of page junction ²), so measurement result also has other energy: comprise the energy (Dissipated Energy) that is scattered in the network of fibers as page layering mensuration except the binding energy that comprises fiber and fiber; Z comprises fibrous inside in conjunction with breaking merit (Intrafiber Bond FailureEnergy) to the bond strength mensuration.In addition, these three kinds of methods are all just measured fiber a merit of breaking above the area of plane, and in fact the bonded area of fiber is not a pure flat area but individual three-dimensional area; Even in the area of plane of experiment definition, fiber is not all combinations fully on whole plane yet, and just in the combination of limited place, therefore the area that breaks in the experiment is bigger than actual bonded area.So these three kinds of methods can not draw the shear resistance value of absolute single fiber.Though ultrasonic Method for Measuring can realize measuring in real time, and is insensitive to the bond strength that chemical assistant improves.Aspect the microscopic measurement method, Mohlin is micro-amplification with his a self-designed cover cardinal principle, and the device of Fiber～Cellophane by name is measured the shearing bond strength and the bonded area of single fiber; Stratton designs the measurement mechanism of cover FLER2 by name and measures interfibrous shearing bond strength and bonded area; Nordman has adopted and the measuring method that absorbs a kind of shearing bond strength that can be relevant with Rennel; Mayhood designs the equipment of a cover Moving Mount and measures interfibrous shearing bond strength.Above researchist studies the shearing bond strength influence of single fiber beating degree, and the apparatus measures of design very complexity is difficult to operation, and measurement takes time and effort.

Summary of the invention

The objective of the invention is to overcome the shortcoming and defect of prior art, a kind of special instrument that need not to adopt is provided, be not subjected to the influence of factors such as quantitative and auxiliary agent, simple to operate, be easy to realize the method for the measurement shearing bond strength between fibers that applicability is good.

Purpose of the present invention is achieved through the following technical solutions: a kind of method of measuring shearing bond strength between fibers comprises the steps---

(A) under certain wet pressing and certain beating degree, measure fibre morphology parameter coefficient k; Be specially:

Measure the fibre coarseness (c) of fiber, fiber girth (P), fibre length (L) is calculated the k value according to formula (1).

$k=\frac{12c}{\mathrm{PL}}---\left(1\right)$

(B) the zero distance tensile strength Z of measurement page, tensile strength T, light-scattering coefficient S.

(C) calculate training film-substrate binding strength index (Page Bonding Strength Index, PBSI, Nmg according to formula (2) ^～1)

$\mathrm{PBSI}={[\frac{1}{T}-\frac{9}{8Z}]}^{-1}---\left(2\right)$

(D) relation of derivation training film-substrate binding strength indices P BSI and light-scattering coefficient S; Be specially: the area of combination with relative bonded area RBA definition as the formula (3).

$\mathrm{RBA}=\frac{S_0-S}{S_0}---\left(3\right)$

In the formula: RBA---relative bonded area, %; The light-scattering coefficient of S---page, m ²/ kg;

S ₀---the complete unconjugated light-scattering coefficient of page, m ²/ kg;

The equation that Pei Ji (PAGE) calculates tensile strength is suc as formula (4):

$\frac{1}{T}=\frac{9}{8Z}+\frac{12c}{\mathrm{bPL}\left(\mathrm{RBA}\right)}---\left(4\right)$

Wherein, T---tensile index, Nm/g; Z---zero distance tensile strength, Nm/g;

C---fibre coarseness, mg/100m; B---the shear resistance of fiber unit's bonded area, N/m ²

P---fiber girth, μ m; L---fibre length, mm;

RBA---relative bonded area, %;

In wushu (3) substitution (4), can get formula (5)

${[\frac{1}{T}-\frac{9}{8Z}]}^{-1}=\frac{b}{k}-\left[\frac{b}{k{S}_0}\right]S---\left(5\right)$

Wushu (1) and formula (2) substitution (5) promptly have

$\mathrm{PBSI}=\frac{b}{k}-\left[\frac{b}{k{S}_0}\right]S---\left(6\right)$

(E) draw the graph of a relation of training film-substrate binding strength indices P BSI and light-scattering coefficient S; Be specially:

Constant pressure changes beating degree, and repeating step (1), (2), (3) obtain training film-substrate binding strength indices P BSI and light-scattering coefficient S value under the different beating degree situations, draws both sides relation figure.

(F) calculate shearing bond strength b value by graph of a relation; Specifically: calculate shearing bond strength b value by the coefficient before the light-scattering coefficient S of graph of a relation.

The present invention has following advantage and effect with respect to prior art: the present invention is to train base (PAGE) binding isotherm, and in conjunction with the light-scattering coefficient measuring technique, work out a kind of simple measurement and calculate the method for single fiber shearing bond strength, this method need not to adopt special instrument, be not subjected to the influence of factors such as quantitative and auxiliary agent, simple to operate, be easy to realize, applicable to the measurement of all pages, adaptability is good.

Description of drawings

Fig. 1 is the fibre-diagram under the different beating degrees.

Fig. 2 is a graph of relation of training film-substrate binding strength indices P BSI and light-scattering coefficient S under the different beating degrees.

Embodiment

The present invention is described in further detail below in conjunction with embodiment and accompanying drawing, but embodiments of the present invention are not limited thereto.

Embodiment

The slurry that present embodiment adopts is: bleach Canadian kraft pine slurry

The experimental apparatus and the equipment that use comprise:

LabTech PFI mill;

The standard fibers discretizer;

The degree Schopper-Riegler instrument;

The LabTech handshcet former;

Mesmer standard sheet press;

FS～200 fibre analysis devices;

The OLYMPUS microscope;

Lorentoen ﹠amp; Wettre tensile strength tester;

TechniBriten Miroo TB～1C whiteness instrument;

PUCMAC Z～Span1000 zero distance tensile strength instrument;

The experimentation of present embodiment comprises:

1) be equipped with slurry: pulpboard was soaked in water 12 hours, tears up, use the pulp screen screening the pulp, keep long fibre, it is standby to dewater.

2) making beating: measure moisture content, get and be equivalent to the 30g oven dry stock,, measure beating degree and fibre length L, girth P, rugosity c with the making beating of PFI mill.

3) copy sheet: on the standard handshcet former, copy sheet.

4) wet pressing: according to requirement of experiment the l Water Paper that is ferreted out is carried out wet pressing, oven dry, constant temperature and humidity 24 hours.

The method of this measurement shearing bond strength between fibers also comprises the steps:

(A) measure fibre morphology parameter coefficient k

In order to guarantee the length homogeneity of fiber, experiment is pulled an oar to fiber with the PFI mill, the not cut staple of trying one's best, and based on wire-dividing broom purification.Experiment measuring different beating degrees fibre length is influenced, the result is as shown in table 1.

Fibre morphology under the different beating degrees of table 1

No

Making beating rotating speed/Rev.

Beating degree/° SR

Fibre length (double weight average length)/mm

Fibre coarseness/mg (100m) ～1

Fiber girth/μ m

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

0 2000 4000 6000 8000 10000 12000 14000 16000 18000 20000 22000 24000 26000 28000 30000

12 16.5 17 18 20 22 23 26 28.5 31.5 33.5 36 43.5 44.5 46 52

2.53 2.24 2.23 2.01 1.73 1.72 1.70 1.70 1.68 1.67 1.66 1.64 1.59 1.49 1.47 1.45

- - - - - 17.9 18.0 18.1 18.0 18.2 18.1 18.2 - - - -

- - - - - 58.1 58 58.1 58.2 58.1 58.3 58.3 - - - -

By table 1, can draw the fibre length under the different beating degrees, distribute as shown in Figure 1.As seen from Figure 1, along with the raising of making beating revolution and the rising of beating degree, the length of fiber descends to some extent, but between 8000～22000Rev. (20～35 ° of SR), length does not almost change (1.68 ± 0.045mm), the coefficient of variation is 2.67%, and therefore experiment may be selected in this scope and carries out.We select 10000～22000Rev. to carry out next step experiment.

Fibre coarseness and the circumferential measurements result of making beating revolution 10000～22000Rev. also are listed in the table 1, and it can be seen from the table, along with the rising of beating degree, the rugosity of fiber is 18.07 ± 0.17mg (100m) ^～1With girth be 58.15 ± 0.15 μ m, variation range be the experiment error range in.

Therefore, between making beating revolution 10000～22000Rev., fibre length L, rugosity c and girth P are tending towards constant, therefore can be according to their mean value, convolution (1) calculates the k value and is

$k=\frac{12c}{\mathrm{PL}}=\frac{12\×18\×{10}^{-5}}{58.2\×{10}^{-9}\×1.68}g/m^3=2.20\×{10}^{4}g/m^3---\left(7\right)$

(B) the zero distance tensile strength Z of measurement page, tensile strength T, light-scattering coefficient S.

In 10000～22000Rev. making beating, then l Water Paper at 4.0bar (4.0 * 10 ⁵N/m ²) pressure squeezing down, copy paper; (%) 50% time constant temperature (23 ℃) constant humidity is 24 hours for Relative Humidity, RH at relative air humidity.Measure tensile strength index T, zero distance tensile strength index Z and the light-scattering coefficient S of the page under the different beating degrees under this humidity of this pressure.The result is as shown in table 2.

Table 2 4bar pressure, 50%RH, the Z of the page of different beating degrees, T and S

Making beating revolution/Rev.	Beating degree/° SR	Zero distance tensile strength index/Nmg ～1	Tensile strength index/Nmg ～1	Light-scattering coefficient/m 2kg ～1
					10000 12000 14000 16000 18000 20000 22000	22 23 26 28 31 33 36	200 202 208 212 216 219 221	53.66 58.7 60.68 62.64 66.55 67.27 67.75	28.89 27.97 27.19 27.06 26.19 26.17 25.43

(C) calculate training film-substrate binding strength index (Page Bonding Strength Index, PBSI, Nmg ^～1); Specifically be to calculate training film-substrate binding strength indices P BSI value by the data based formula (2) of table 2.

(D) draw the graph of a relation of training film-substrate binding strength indices P BSI and light-scattering coefficient S.Can train the relation curve of film-substrate binding strength indices P BSI association index and light-scattering coefficient S by table 2, as shown in Figure 2; As can be seen from Figure 2, light-scattering coefficient S and training film-substrate binding strength indices P BSI have the better linearity relation.Convolution (5), as can be known in beating degree when 22～36 ° of SR change, intercept Be tending towards constant, k is tending towards constant in this making beating scope simultaneously, and therefore can get b also is tending towards constant.Promptly in this making beating scope, making beating can not change shearing bond strength b effectively.

(E) calculate shearing bond strength b value by graph of a relation

Can get by Fig. 3,4.0bar pressure, under relative humidity 50% condition, the relation equation of light-scattering coefficient S and training film-substrate binding strength indices P BSI is under the different beating degrees

PBSI _{4.0bar，50％RH}＝-8.1517S _{4.0bar，50％RH}+313.73..........................(8)

Contrast formula (5) and formula (8) have

$\frac{b}{k{S}_0}=8.1517---\left(9\right)$

$\frac{b}{k}=313.73---\left(10\right)$

Convolution (5) can get S by formula (9) and formula (10) ₀Be 38.49m ²Kg ^～1, b is 6.90 * 10 ⁶Nm ^～2

Therefore, just calculated under 4bar pressure, the fiber shearing adhesion of bleaching Canadian kraft pine slurry is 6.90 * 10 ⁶Nm ^～2

The foregoing description is a preferred implementation of the present invention; but embodiments of the present invention are not restricted to the described embodiments; other any do not deviate from change, the modification done under spirit of the present invention and the principle, substitutes, combination, simplify; all should be the substitute mode of equivalence, be included within protection scope of the present invention.

Claims (4)

1, a kind of method of measuring shearing bond strength between fibers is characterized in that comprising the steps:

(A) under certain wet pressing and certain beating degree, measure fibre morphology parameter coefficient k;

(B) the zero distance tensile strength Z of measurement page, tensile strength T, light-scattering coefficient S;

(C) calculate training film-substrate binding strength indices P BSI;

(D) draw the graph of a relation of training film-substrate binding strength indices P BSI and light-scattering coefficient S;

(E) calculate shearing bond strength b value by graph of a relation.

2, the method for measurement shearing bond strength between fibers according to claim 1 is characterized in that: described step (A) is the fibre coarseness c of measurement fiber, fiber girth P, and fibre length L calculates the k value according to following formula; $k=\frac{12c}{\mathrm{PL}}.$

3, the method for measurement shearing bond strength between fibers according to claim 1 is characterized in that: described step (C) is for calculating training film-substrate binding strength indices P BSI according to following formula;

$\mathrm{PBSI}={[\frac{1}{T}-\frac{9}{8Z}]}^{-1}.$

4, the method for measurement shearing bond strength between fibers according to claim 1 is characterized in that: described step (E) is to calculate shearing bond strength b value by the coefficient before the light-scattering coefficient S of the described graph of a relation of step (D).

Images